Compression bonding device

ABSTRACT

A compression bonding device capable of packaging electric components on both sides of a substrate is provided. A compression bonding device includes first and second pressing rubbers. Electric components can be simultaneously packaged on the front face and the rear face of a substrate by sandwiching the substrate between the first and second pressing rubbers. The electric components are not subjected to a force for horizontally moving them because the first and second pressing rubbers are prevented from horizontal extension by a first dam member. Thus, the electric components are connected to the substrate without misalignment, thereby obtaining a highly reliable electric device.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of International ApplicationNo. PCT/JP2007/052217 filed on Feb. 8, 2007, which claims priority toJapan Patent Application No. 2006-033745, filed on Feb. 10, 2006, theentire disclosures of which are hereby incorporated by reference hereinin their entireties.

BACKGROUND

The present disclosure generally relates to a compression bonding devicefor packaging electric components on a substrate.

Conventionally, packaging processes for connecting electric componentssuch as semiconductor elements to a substrate have used a compressionbonding device by which the electric components are pressed against thesubstrate with a pressing head under heat.

Reference numeral 101 in FIG. 14( a) represents a conventionalcompression bonding device. The compression bonding device 101 has apedestal 126 and a pressing head 120.

The pressing head 120 has a pressing rubber fitted into a metal frame,or a pressing rubber bonded to a metal plate with an adhesive or aliquid rubber cast into a metal frame and cured within the metal frame,etc.

In the case of a pressing rubber 122 fitted into a head body 121 made ofa metal frame, the surface of the pressing rubber 122 is flush with thesurface of the head body 121 or projects below the surface of the headbody 121. When the pressing head 120 is pressed against an object to bepressed 110 on the pedestal 126, the surface of the pressing rubber 122comes into contact with the object to be pressed 110.

The object to be pressed 110 has a substrate 111 and electric components116, 118 having different thicknesses placed on the substrate 111 sothat steps are formed on the substrate 111 due to the thicknessdifferences between the electric components 116 and 118.

The pressing rubber 122 is formed from an elastic material that deformsunder pressure. The pressing rubber 122 first comes into contact withthe thickest electric component 116. Then, the pressing rubber 122deforms and successively comes into contact with the electric componentsin the order of thickness from the thickest 116 to thinnest 118.Finally, all of the electric components 116, 118 are pressed by thepressing rubber 122.

Before the electric components 116, 118 are pressed by the compressionbonding device 101, the electric components 116, 118 and the substrate111 are aligned; and terminals of the electric components 116, 118 aredirectly above terminals of the substrate 111 with an adhesive 115inserted therebetween.

The surface of the pedestal 126 is nearly horizontal, and the substrate111 is horizontally placed on that surface. When the pressing head 120is vertically moved downward to press the electric components 116, 118while the object to be pressed 110 is heated, the electric components116, 118 thrust the adhesive 115 aside to move right below, whereby theterminals of the electric components 116, 118 and the terminals of thesubstrate 111 come into contact with each other to electrically connectthe electric components 116, 118 and the substrate 111 (FIG. 14( b)).Thus, the conventional compression bonding device 101 can simultaneouslyconnect electric components having different thicknesses to onesubstrate.

However, if the pressing rubber 122 is depressed when it pressescomponents 116, 118, the pressing rubber 122 has the property of bulgingaround the depressed part. Therefore, the bulging part of the pressingrubber 122 extends over the frame of the head body 121 with the resultthat the surface of the pressing rubber 122 extends horizontallyoutward.

FIG. 15 is a plan view for showing the manner in which the surface ofthe pressing rubber 122 extends horizontally outward, i.e., the pressingrubber 122 radially flows around the center C of the planar shape. Dueto the greater amount of movement at the periphery of the pressingrubber 122 as compared with the vicinity of the center C, the electriccomponents 116, 118 pressed by the periphery of the pressing rubber 122horizontally move as the pressing rubber 122 extends, whereby theterminals of the electric components 116, 118 are misaligned from thelocation directly above the terminals of the substrate 111.

If the electric components 116, 118 are misaligned, the terminals of theelectric components 116, 118 fail to come into contact with theterminals of the substrate 111, resulting in the deterioration of areliable connection between the electric components 116, 118 and thesubstrate 111.

When the electric components 116, 118 are to be packaged on not only oneside of the substrate 111 but also the other side thereof, a longer timeis required for packaging because the electric components 116, 118 needto be packaged on each side of the substrate 111 in twice.

Especially in a process for packaging the electric components 116, 118on one side and then packaging the electric components 116, 118 on theother side, a pattern corresponding to the shapes of the electriccomponents 116, 118 need to be formed on the pedestal 126 so as toprotect the packaged electric components 116, 118 against damages bypressing because the side on which the electric components 116, 118 havealready been packaged faces the pedestal 126.

In this method, however, the pedestal 126 must be newly prepared eachtime when the types of the electric components 116, 118 and thesubstrate 111 or the locations at which the electric components 116, 118are to be connected are changed.

Moreover, the electric components 116, 118 can be damaged by repeatedlyheating and pressing because the electric components 116, 118 packagedon one side, are heated and pressed again when the electric components116, 118 are connected to the other side. See, Patent Document Nos. JP A2002-359264 and JP A 2005-32952.

SUMMARY

The present embodiments are directed toward solving the problemsdescribed above, with the purpose of providing a compression bondingdevice capable of reliably connecting electric components and asubstrate.

In an embodiment, a compression bonding device is provided includingfirst and second pressing rubbers. The first and second pressing rubbersare configured so that an object to be pressed which is placed betweenthe first and second pressing rubbers can be pressed by the first andsecond pressing rubbers. A dam member is positioned higher than asurface level of the first pressing rubber is placed around the firstpressing rubber, and the second pressing rubber can be inserted into aspace surrounded by the dam member.

In an embodiment, a compression bonding device is provided includingfirst and third pressing rubbers. The first and third pressing rubbersare configured so that an object to be pressed, which is placed betweenthe first and third pressing rubbers, can be pressed by the first andthird pressing rubbers. A dam member positioned higher than a surfacelevel of each of the first and third pressing rubbers is placed aroundeach of the first and third pressing rubbers.

In an embodiment, the compression bonding device including the firstpressing rubber which is placed on a first pressing plate, includes afirst compression member, which is compressively deformable and placedbetween the first pressing rubber and the first pressing plate. Thefirst dam member becomes higher than the surface level of the firstpressing rubber at least when the first compression member iscompressed.

In an embodiment, a compression bonding device is provided includingfourth and fifth pressing rubbers. The fourth and fifth pressing rubbersare configured so that an object to be pressed, which is placed betweenthe fourth and fifth pressing rubbers, can be pressed by the fourth andfifth pressing rubbers. The compression bonding device has a dam membersurrounding the fourth and fifth pressing rubbers, and the dam member isseparable from the fourth and fifth pressing rubbers.

In an embodiment of the compression bonding device, wherein the dammember is tubular, and the fourth and fifth pressing rubbers can beinserted into the tube of the dam member.

According to the embodiment defined above, both a front face and a rearface of a substrate are simultaneously pressed by sandwiching thesubstrate between first and second pressing rubbers, whereby electriccomponents can be simultaneously connected to both the front face andthe rear face of the substrate.

The time required for packaging processes can be shortened and electriccomponents are less damaged by heating and pressing because the electriccomponents can be simultaneously connected to a front face and a rearface of a substrate. Highly reliable electric devices can be obtainedbecause the electric components horizontally move on neither the frontface nor the rear face of the substrate and the electric components arenot misaligned. As a result of the absence of horizontal extension ofthe pressing rubber when an object to be pressed is pressed, nearly thetotal force for deforming the pressing rubber converts into a force forpressing the object to be pressed, thereby avoiding wasted pressure whenthe object is pressed.

Additional features and advantages are described herein, and will beapparent from, the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional diagram for illustrating a compression bondingdevice according to a first embodiment;

FIG. 2 is a plan view for illustrating the geometry of the pressing headand the pedestal;

FIG. 3( a)-(c) are sectional diagrams for illustrating a process forpackaging electric components on a substrate;

FIGS. 4( a) and (b) are enlarged sectional diagrams for illustrating aprocess by which the electric components are connected to the substrate;

FIG. 5( a)-(c) are sectional diagrams for illustrating a process forpackaging electric components using a compression bonding deviceaccording to a second embodiment;

FIG. 6 is a sectional diagram for illustrating another embodiment of thecompression member;

FIG. 7 is a sectional diagram for illustrating a compression bondingdevice according to a third embodiment;

FIG. 8( a)-(c) are sectional diagrams for illustrating a process forpackaging electric components on a substrate;

FIG. 9( a)-(c) are sectional diagrams for illustrating a process forpackaging electric components on a substrate using a compression bondingdevice according to a fourth embodiment;

FIG. 10( a) is a sectional diagram for showing a state in which a dammember is separated from fourth and fifth pressing rubbers; FIG. 10( b)is a sectional diagram for showing a state in which a dam membersurrounds fourth and fifth pressing rubbers;

FIG. 11 is a plan view for illustrating an embodiment of a dam member;

FIG. 12 is a plan view for illustrating another embodiment of a dammember;

FIG. 13 is a side view for illustrating a dam member having slits;

FIGS. 14( a) and (b) are sectional diagrams for illustrating aconventional compression bonding device;

FIG. 15 is a plan view for illustrating extension of a pressing rubber.

DETAILED DESCRIPTION

Reference numeral 1 in FIG. 1 represents a compression bonding deviceaccording to a first embodiment, and this compression bonding device 1has first and second pressing heads 10, 20, a platform 9, and a driveunit 2. The first pressing head 10 has a metal head body 11, a hole 19having the bottom face formed in the head body 11, and a first pressingrubber 15 placed in the hole 19.

The first pressing rubber 15 has a columnar shape in horizontal sectionnearly identical to the sectional shape of a part surrounded by a firstdam member 16 and has a bottom face in close contact with the bottomface of the hole 19 and a side face in contact with the side wall of thehole 19.

The height of the first pressing rubber 15 from the bottom face to thesurface is lower than the depth of the hole 19 and the first pressingrubber 15 is surrounded by the first dam member 16 formed by the sidewall of the holes 19; and a concave 17, which has the surface of thefirst pressing rubber 15 as a bottom face and the first dam member 16 asa side face, is formed between the surface of the first pressing rubber15 and the edge of the first dam member 16.

The first pressing head 10 is placed in such a manner that the surfaceof the first pressing rubber 15 is nearly horizontal with the opening 18of the concave 17 facing downward.

The part of the first head body 11 in close contact with the bottom faceof the first pressing rubber 15 is a first pressing plate 12, and thefirst pressing plate 12 is fitted to the drive unit 2 via a shaft 3. Thefirst pressing plate 12 is configured in such a manner that when thedrive unit 2 is activated and the shaft 3 is extended and retracted, thefirst pressing plate 12 vertically moves upward and downward togetherwith the first pressing rubber 15 and the first dam member 16 while thesurface of the first pressing rubber 15 remains nearly horizontal.

The platform 9 is placed at a position right below the first pressinghead 10, and the second pressing head 20 is placed on the platform 9.

The second pressing head 20 has a second head body 21 formed from ametal pressing plate and a second pressing rubber 25 placed on thesurface of the second head body 21, and the second pressing head 20 isin close contact with the platform 9 on the side of the second head body21 while it faces upward on the side of the second pressing rubber 25.Thus, the surface of the second pressing rubber 25 is exposed on theupper face of the second pressing head 20.

Here, nothing is placed around the second pressing rubber 25, and theplanar shape of the second pressing rubber 25 is a similar figure whichis identical to or smaller than the aforementioned opening 18 of theconcave 17 (FIG. 2) and at least the upper end of the second pressingrubber 25 of the second pressing head 20 can be inserted into theconcave 17.

Next, an object to be pressed that can be pressure-bonded using thiscompression bonding device 1 and a process for pressure-bonding theobject to be pressed 30 are explained.

Reference numeral 30 in FIG. 4( a) represents an object to be pressed,and the object to be pressed 30 has a substrate 31, an adhesive film 35,and electric components 32, 33.

Terminals 37 are formed on the front face and the rear face of thesubstrate 31, and the adhesive film 35 is placed on the terminals 37 onthe front face of the substrate 31 and on the terminals 37 on the rearface of the substrate 31.

The electric components 32, 33 have terminals 38, 39 such as bumps orlands, and the electric components 32, 33 are aligned so that theterminals 38, 39 lie above the terminals 37 of the substrate 31, andthen individually mounted on the adhesive film 35 by a mounting head notshown, and pressed by a small pressure with the mounting head while theyare heated at a relatively low temperature, whereby they areprovisionally bonded to the front face and the rear face of thesubstrate 31 by an adhesive force developed by the adhesive film 35(provisional compression bonding).

However, the adhesive force is so weak that the electric components 32,33 readily drop off the substrate 31 by physical impacts, and theterminals 37 of the substrate 31 and the terminals 38, 39 of theelectric components 32, 33 are in neither physical nor mechanicalcontact with each other and the adhesive film 35 exists am ong theterminals 37, 38, 39.

The adhesive film 35 is larger than the planar shapes of the electriccomponents 32, 33, and partially extends over the electric components32, 33, and it is exposed between the electric components 32, 33. Evenif the adhesive film 35 is not exposed from the electric components 32,33, the adhesive film 35 will partially extend over the outerperipheries of the electric components 32, 33 by pressing the electriccomponents during the pressing step described below.

The first and second pressing rubbers 15, 25 are formed from a materialthat can be bonded to the adhesive film 35. Therefore, a protective film5 having low adhesiveness to the adhesive film 35 is placed on thesurface of the second pressing rubber 25 so as to prevent the secondpressing rubber 25 from contacting the adhesive film 35, and then theobject to be pressed 30 is placed on the second pressing rubber 25 withthe front face of the substrate 31 upward and the rear face downward(FIG. 3( a)).

Here, the surface of the second pressing rubber 25 is horizontal, andthe protective film 5 has a uniform thickness. Thus, the part of thesurface of the protective film 5 on the second pressing rubber 25 isnearly horizontal.

The electric components 32, 33 having different thicknesses are bondedon the rear face of the substrate 31, but the substrate 31 is nearlyhorizontal because the thickest electric components 32 are apart fromeach other on the rear face of the substrate 31 or otherwise anauxiliary component for supporting the substrate 31 is placed on thesecond pressing rubber 25 to hold the substrate by the electriccomponents 32 or auxiliary component.

Then, the protective film 5 is also placed on the object to be pressed30 to prevent the first pressing rubber 15 from contacting the adhesivefilm 35, and the front face and the rear face of the object to bepressed 30 are covered with the protective film 5.

If the protective film 5 is larger than the planar shape of the secondpressing rubber 25 and the protective film 5 on the second pressingrubber 25 or the protective film 5 on the object to be pressed 30 hangsalong the side face of the second pressing rubber 25, the planar shapeof the second pressing rubber 25 is smaller than the opening 18 of theconcave 17 and the outer shape of the second pressing rubber 25including the hanging protective film 5 approximately equals to the sizeof the opening 18.

The planar shape of the object to be pressed 30 is identical to orsmaller than the planar shape of the second pressing rubber 25 and theouter periphery of the object to be pressed 30 lies not to extend overthe second pressing rubber 25. When the first and second pressing heads10, 20 are aligned so as to conform the outer periphery of the secondpressing rubber 25 including the protective film 5 to the opening 18 andthen the first pressing head 10 is lowered, the object to be pressed 30is inserted into the concave 17 of the first pressing head 10.

When the thickness of the object to be pressed 30 is supposed to be thetotal of the thickness of the thickest electric components 32 on thefront face of the substrate 31 plus the thickness of the thickestelectric components 32 on the rear face of the substrate 31 plus thethickness of the substrate 31, the depth of the concave 17, i.e., theheight of the edge of the first dam member 33 from the surface of thefirst pressing rubber 15 is equal to or greater than the total of thethickness of the object to be pressed 30 plus the thickness of theprotective film 5 covering the front face and the rear face of theobject 30, whereby the object to be pressed 30 enters the concave 17entirely from the front face to the rear face.

If the depth of the concave 17 is greater than the total of thethickness of the object to be pressed 30 plus the thickness of theprotective film 5, the first pressing head 10 descends even after theobject to be pressed 30 has entered the concave 17, and the edge of thefirst dam member 16 does not press the surface of the second pressingrubber 25 and the first pressing head 10 does not stop descendingbecause the outer shape of the second pressing rubber 25 including theprotective film 5 is approximately equal to the size of the opening 18.

The protective film 5 is formed from a compressively deformablematerial. Therefore, even if the outer shape of the second pressingrubber 25 including the protective film 5 is slightly larger than theopening 18, the first pressing head 10 does not stop descending becausethe protective film 5 compressively deforms and enters the clearancebetween the second pressing rubber 25 and the first dam member 16.

When the first pressing head 10 is continuously lowered, the object tobe pressed 30 and the first pressing rubber 15 move closer to eachother.

If multiple types of electric components 32, 33 having differentthicknesses are bonded to the front face of the substrate 31, steps areformed on the front face of the substrate 31 by the thicknessdifferences. Here, the surface of the first pressing rubber 15 is nearlyhorizontal and the first pressing head 10 is vertically lowered.Therefore, if the first pressing head 10 is continuously lowered, thesurface of the first pressing rubber 15 comes into contact with thethickest electric components 32 among the electric components 32, 33bonded to the front face of the substrate 31 via the protective film 5.

FIG. 3( b) shows a state in which the first pressing rubber 15 is incontact with only the thickest electric components 32 before it pressesthe electric components 32, 33 on the front face of the substrate 31,and in this state where the first pressing rubber 15 is in contact withthe thickest electric components 32, the edge of the first dam member 16is flush with the plane H on which the surface of the second pressingrubber 25 lies or below it because the depth of the concave 17 is equalto or greater than the thickness of the object to be pressed 30including the protective film 5.

The first and second pressing rubbers 15, 25 are formed from an elasticmaterial that deforms when a force is applied and restores the originalshape when the force is removed (e.g., elastomer). The first and secondpressing rubbers 15, 25 are deformable at not only central parts butalso peripheral parts because the side face of the first pressing rubber15 is in contact with the inner wall of the hole 19 but not fixed to theinner wall and nothing is placed around the second pressing rubber 25.

Thus, when the first pressing head 10 is lowered from the state shown inFIG. 3( b) to press the object to be pressed 30 by the first and secondpressing rubbers 15, 25, the parts of the first and second pressingrubbers 15, 25 having come into contact with the electric components 32are depressed independently of whether they are central or peripheral.

When the first pressing head 10 is further lowered to bring the firstand second pressing rubbers 15, 25 relatively close to each other, theelectric components are successively pressed against the first andsecond pressing rubbers 15, 25 in the order of thickness from thickerones 32 to thinner ones 33, and finally all of the electric components32, 33 are pressed against the substrate 31.

The first and second pressing rubbers 15, 25 are formed from a materialthat is depressed in loaded parts and bulges in other parts such as aninternally homogeneous elastic material, and the parts of the firstpressing rubber 15 out of contact with the electric components 32, 33bulge downward, while the parts of the second pressing rubber 25 out ofcontact with the electric components 32, 33 bulge upward.

At least the surface part of the deformed second pressing rubber 25entered into the concave 17 and the side face of the part entered intothe concave 17 is surrounded by the first dam member 16 even if thesurface of the second pressing rubber 25 before deformation is flushwith the edge of the first dam member 16 because the first and secondpressing rubbers 15, 25 are closer to each other than before they aredeformed.

The side face is in close contact with the first dam member 16 or evenif a clearance exists between the side face and the first dam member 16,the clearance is too narrow for the bulging first pressing rubber 15 toflow out from the clearance. Therefore, the first pressing rubber 15does not extend horizontally. Even if the part of the second pressingrubber 25 entered into the concave 17 extends horizontally, theextension is negligible because of the narrow clearance.

Thus, the side face of the part of the second pressing rubber 25 enteredinto the concave 17 is in close enough contact with the first dam member16 so as to prevent horizontal extension of the first and secondpressing rubbers 15, 25, whereby the bulging parts of the first andsecond pressing rubbers 15, 25 may be filled in the voids between theelectric components 32 and 33 but does not flow horizontally (i.e., inthe direction perpendicular to the moving direction of the firstpressing head 10).

No outward force is exerted on the electric components 32, 33 and theelectric components 32, 33 are pressed against the adhesive film 35 atthe same positions as those of provisional compressing bonding becausethe surface parts of the first and second pressing rubbers 15, 25 do notextend horizontally.

Here, the second head body 21 has a heater 28 so that the object to bepressed 30 is heated at a predetermined temperature by activating theheater 28, and the flowability of the adhesive film 35 is increased byheating.

Thus, when the electric components 32, 33 are pressed against theadhesive film 35, the adhesive film 35 is thrust aside and the terminalsof the electric components 32, 33 are forced into the adhesive film 35so that the terminals 38, 39 of the electric components 32, 33 directlycome into contact with the terminals 37 of the substrate 31, whereby theelectric components 32, 33 and the substrate 31 are electricallyconnected to each other.

If the adhesive film 35 contains a thermosetting resin, the adhesivefilm 35 is cured by heating, and if the adhesive film 35 contains athermoplastic resin, the adhesive film 35 becomes solidified when thetemperature drops after completion of heating.

Thus, the electric components 32, 33 are also mechanically connected tothe substrate 31 via the cured or solidified adhesive film 35, therebyobtaining an electric device 30 a (FIG. 3( c)).

If the electric components 32, 33 are misaligned when they are pressed,the reliability of the electric device 30 a is deteriorated because theterminals 38, 39 of the electric components 32, 33 fail to come intocontact with the terminals 37 of the substrate 31, but the electricdevice 30 a prepared by using the compression bonding device 1 of thepresent embodiment is highly reliable because the electric components32, 33 are not misaligned by using the compression bonding device 1 ofthe present embodiment as described above.

Even if the adhesive film 35 extends over the outer peripheries of theelectric components 32, 33 when the electric components 32, 33 arepressed, the first and second pressing rubbers 15, 25 do not directlycome into contact with the adhesive film 35 because a protective film 5lies between the first pressing rubber 15 and the object to be pressed30, and between the second pressing rubber 25 and the object to bepressed 30.

Thus, the first and second pressing rubbers 15, 25 are not bonded to theadhesive film 35, and when the first pressing head 10 is moved upward,the first pressing rubber 15 is separated from the electric device 30 a,and when the electric device 30 a is raised, the electric device 30 a isseparated from the second pressing rubber 25, whereby the electricdevice 30 a can be removed from the compression bonding device 1.

The foregoing description relates to cases in which the object to bepressed 30 is entered into the concave 17 preliminarily formed in thepressing head 10 and then the first pressing rubber 15 is contacted withthe object to be pressed 30, but the embodiments are not limited to suchcases.

Reference numeral 4 in FIG. 5( a) represents a compression bondingdevice according to a second embodiment, and this compression bondingdevice 4 has the same structure as that of the compression bondingdevice 1 according to the first embodiment and the layout of the firstand second pressing heads 10, 20 is also similar except that a firstcompression member 46 is placed between the first pressing rubber 15 andthe first pressing plate 12.

In contrast to the first pressing rubber 15, which is formed from aninternally homogeneous elastic material as described above, the firstcompression member 46 is formed from a material having internal voidsthat are collapsed under pressure to decrease the volume, such assponge-like rubber.

A movable plate 47 is placed between the first pressing rubber 15 andthe first compression member 46, and the first compression member 46 isfitted to the surface of the first pressing plate 12 at the upper endand to the surface of the movable plate 47 at the lower end, while theupper end of the first pressing rubber 15 is fitted to the bottom faceof the movable plate 47. Thus, the first compression member 46, movableplate 47, and first pressing rubber 15 are arranged in theaforementioned order from the first pressing plate 12 in a verticaldownward direction.

Similarly to the first pressing rubber 15, the first compression member46 has the same columnar shape in horizontal section as the sectionalshape of a part surrounded by the first dam member 16, and the side faceof the first compression member 46 is in contact with the first dammember 16.

However, the side face of the first compression member 46 is not fixedto the first dam member 16, and neither first pressing rubber 15 normovable plate 47 is fixed to the first dam member 16. Thus, the firstpressing rubber 15 and the movable plate 47 are movable within the partsurrounded by the first dam member 16 when the thickness of the firstcompression member 46 changes.

To prepare an electric device using this compression bonding device 4,the object to be pressed 30 is placed on the second pressing rubber 25via the protective film 5 and the first pressing rubber 15 is brought tocontact with the thickest electric component 32 via the protective film5 in the same manner with the compression bonding device 1 according tothe first embodiment.

The force required to deform the first compression member 46 is smallerthan the force required to deform the first and second pressing rubbers15, 25. When the first pressing head 10 is further lowered to press thefirst pressing plate 12 against the first compression member 46, thefirst compression member 46 is compressed to reduce the thickness beforethe first and second pressing rubbers 15, 25 deform.

As described above, the first pressing rubber 15 is movable within thepart surrounded by the first dam member 16, and therefore, when thethickness of the first compression member 46 is reduced, the firstpressing rubber 15 moves upward to form a concave that has not existedbefore the first compression member 46 is compressed, and the object tobe pressed 30 is entered into the concave.

The compression of the first compression member 46 stops when it deformsto some extent due to the limitation of the amount by which the firstcompression member 46 deforms.

FIG. 5( b) shows a state in which the compression of the firstcompression member 46 stops before the first and second pressing rubbers15, 25 deform. In this state, the edge of the first dam member 16projects below the surface of the first pressing rubber 15 by a distancethe first pressing rubber 15 has moved upward, whereby the edge is flushwith the plane H on which the surface of the second pressing rubber 15lies or projects below it.

When the first pressing head 10 is further lowered after the firstcompression member 46 stops deforming, the first and second pressingrubbers 15, 25 are pressed against the electric components 32, 33 anddepressed while the parts out of contact with the electric components32, 33 bulge, but the surface of the first pressing rubber 15 does notextend horizontally because of the small clearance between the secondpressing rubber 25 and first dam member 16 in the same manner as withthe compression bonding device 1 according to the first embodiment.

Moreover, the surface of the second pressing rubber 25 may bulge upwardbut does not extend horizontally because at least the surface part ofthe second pressing rubber 25 is entered into the concave 17 bydeformation of the first and second pressing rubbers 15, 25. Thus, thiscompression bonding device 4 also prevents horizontal displacement ofthe electric components 32, 33, thereby obtaining a highly reliableelectric device 30 a.

The first compression member 46 is not specifically limited so far as itdecreases the volume by pressing, and the compression member may isformed from a spring 48 as shown in FIG. 6, and the spring 48 iscompressed by pressing the first pressing plate 12 to decrease thelength and raise the surface of the first pressing rubber 15, thusforming a concave. If the force applied to the first pressing rubber 15can be transferred to the first compression member 46, there is nospecial need for providing the movable plate 47.

The foregoing description relates to cases in which the first pressingplate 12 is fitted to the shaft 3 of the drive unit 2 and the firstpressing head 10 is moved to bring the first and second pressing rubbers15, 25 close to each other, but the present invention is not limited tosuch cases, and the second pressing head 20 may be moved while the firstpressing head 10 is fixed, or both of the first and second pressingheads 10, 20 may be moved as far as the first and second pressingrubbers 15, 25 can be relatively moved.

The foregoing description relates to cases in which the object to bepressed 30 is placed on the surface of the second pressing rubber 25 andthen the first pressing head 10 is lowered, but the embodiment is notlimited to such cases.

The second pressing head 20 is placed while the side on which the secondpressing rubber 25 is placed is faced downward and the first pressinghead 10 is placed below the second pressing head 20 while the side onwhich the concave 17 is formed is faced upward. The object to be pressed30 is placed on the bottom face of the concave 17, i.e. the surface ofthe first pressing rubber 15, and then either one or both of the firstand second pressing heads 10, 20 is moved. The first and second pressingrubbers 15, 25 move closer together, and the surface of the secondpressing rubber 25 may be pressed against the object to be pressed 30.

The embodiments are is not limited to cases where the surfaces of thefirst and second pressing rubbers 15, 25 are horizontally oriented, butthe first and second pressing head 10, 20 may be placed in such a mannerthat the surfaces of the first and second pressing rubbers 15, 25 arenearly vertical.

The moving direction of the first and second pressing head 10, 20 aremoved is not specifically limited, either, but they are preferably movednearly in a perpendicular direction to the front face and the rear faceof the substrate 31 to prevent misalignment of the electric components32, 33. Therefore, if the substrate 31 is parallel with the surfaces ofthe first and second pressing rubbers 15, 25, the first and secondpressing head 10, 20 are moved in a nearly perpendicular direction tothe surfaces of the first and second pressing rubbers 15, 25.

The foregoing description relates to cases in which nothing is placedaround the second pressing rubber 25 and its side face is exposed, butthe embodiment is not limited to such cases, and the side face of thesecond pressing rubber 25 may be covered with e.g., a metal thin plate(sliding plate) to prevent the first dam member 16 from rubbing againstthe second pressing rubber 25.

When the second pressing head 20 is entered into the concave 17 in caseswhere the side face of the second pressing rubber 25 is covered with asliding plate, the first pressing rubber 15 does not extend horizontallybecause the sliding plate comes into close contact with the first dammember 16 or even if a clearance exists between the sliding plate andthe first dam member 16, the clearance is too narrow for the bulgingfirst pressing rubber 15 to flow out from it.

The sliding plate has a small thickness so that even if it deforms alongwith the second pressing rubber 25, it comes into contact with the firstdam member 16, to thereby stop deforming. Because of the small clearancebetween the first dam member 16 and the sliding plate before it deforms,the amount of deformation is small, and therefore, the horizontalextension of the second pressing rubber 25 is negligible.

Even if the surface edge of the second pressing rubber 25 bulges toextend over the sliding plate, the amount of horizontal extension overthe sliding plate is small because of the small thickness of the slidingplate as well as the small clearance between the sliding plate and thefirst dam member 16 as described above.

Thus, the electric components 32, 33 are less likely to be misalignedbecause the first and second pressing rubbers 15, 25 do not horizontallyextend, and even if they extend, the amount of extension is negligible.

If the clearance between the first dam member 16 and the second pressingrubber 25 is large in the compression bonding devices 1, 4 according tothe first and second embodiments, the clearance can be filled with theprotective film 5 by covering the side face of the second pressingrubber 25 with the protective film 5.

Thus, the first dam member 16 can be prepared at low costs without usingany metallic mold, and even if the molding precision is low, theclearance between the first dam member 16 and the second pressing rubber25 can be filled by appropriately selecting the thickness of theprotective film 5, to thereby prevent the first pressing rubber 15 fromflowing out from the clearance.

The foregoing description relates to cases in which a dam member isprovided on only the first pressing head 10, but embodiment is notlimited to such cases.

Reference numeral 6 in FIG. 7 represents a compression bonding deviceaccording to a third embodiment, and this compression bonding device 6has a third pressing head 60 in addition to the first pressing head 10described above.

The structures of the first and third pressing heads 10, 60 areidentical, and the first and third pressing heads 10, 60 have first andthird head bodies 11, 61, holes 19, 69 having bottoms (first and thirdholes) formed in the first and third head bodies 11, 61, and first andthird pressing rubbers 15, 65 placed in the first and third holes 19,69, respectively.

The layout of the first and third pressing rubbers 15, 65 is alsosimilar, and the first and third pressing rubbers 15, 65 are surroundedby first and third dam members 16, 66 having the side walls of the firstand third holes 19, 69, respectively. The edges of the first and thirddam members 16, 66 highly project from the surfaces of the first andthird pressing rubbers 15, 65 and first and third concaves 17, 67, whichhave the surface of the first and third pressing rubbers 15, 65 asbottom faces and the first and the third dam members 16, 66 as sidefaces, are formed.

The first and third holes 19, 69 have openings 18, 68 having nearly thesame shape so that when the edges of the openings 18, 68 are aligned andthe first and third pressing heads 10, 60 are pressed against eachother, the edges of the first and third dam members 16, 66 come intocontact with each other.

Here, the layout of the first pressing head 10 and the connection withthe drive unit 2 are the same as described about the first pressing head10 of the compression bonding device 1 according to the firstembodiment, and the first pressing head 10 can be vertically movedupward and downward by the drive unit 2 above the platform 9 while thesurface of the first pressing rubber 15 remains nearly horizontal.

The third pressing head 60 is placed on the platform 9 with the opening68 of the third concave 67 upward, and the bottom face of the thirdconcave 67, i.e. the surface of the third pressing rubber 65 is nearlyhorizontal and forms a mounting face on which the object to be pressed30 is to be mounted.

Next, a process for connecting the object to be pressed 30 describedabove using this compression bonding device 6 is explained.

The first and third pressing rubbers 15, 65 are formed from a materialhaving high adhesiveness to the adhesive film 35, and the protectivefilm 5 described above is placed on the surface of the third pressingrubber 65 to prevent contact with the adhesive film 35 and then theobject to be pressed 30 is placed on the third pressing rubber 65, andthe protective film 5 is also placed on the surface of the object to bepressed 30 (FIG. 8( a)).

The total of the depths of the first and third concaves 17, 67 (i.e.,the total of the height from the surface of the first pressing rubber 15to the edge of the first dam member 16 plus the height from the surfaceof the third pressing rubber 65 to the edge of the third dam member 66)is smaller than the total of the thickness of the object to be pressed30 plus the thickness of the protective film 5 covering the front faceand the rear face thereof.

Thus, when the edges of the openings 18, 68 of the first and thirdconcaves 17, 67 are aligned and then the first pressing head 10 islowered, the surface of the first pressing rubber 15 comes into contactwith the object to be pressed 30 via the protective film 5 before theedges of the first and third dam members 16, 66 come into contact witheach other.

FIG. 8( b) shows a state in which the first pressing rubber 15 is incontact with the surface of the object to be pressed 30 via theprotective film 5 before the first and third pressing rubbers 15, 65press the object to be pressed 30, and in this state, a clearance existsbetween the edge of the first dam member 16 and the edge of the thirddam member 66.

If the parts of the first and third head bodies 11, 61 with which thebottom faces of the first and third pressing rubbers 15, 65 are in closecontact are designated as first and third pressing plates 12, 62, thefirst and third pressing rubbers 15, 65 are fixed to the first and thirdpressing plates 12, 62 at the bottom faces respectively but not fixed tothe first and third dam members 16, 66 at the side faces. The first andthird pressing rubbers 15, 65 are deformable at both central andperipheral parts.

Thus, when the first pressing head 10 is further lowered to bring thefirst and third pressing rubbers 15, 65 relatively close to each other,the electric components are successively pressed against the first andthird pressing rubbers 15, 65 in the order of thickness from thickerones 32 to thinner ones 33 in the same manner as with the compressionbonding device 1 according to the first embodiment, whereby the parts ofthe first and third pressing rubbers 15, 65 out of contact with theelectric components 32, 33 bulge to press the object to be pressed 30.

The pressure for pressing the object to be pressed 30 is predetermineddepending on the thicknesses of the adhesive film 35 and the electriccomponents 32, 33, the temperature at which the adhesive film 35 isheated, etc.

The aforementioned total of the depths of the first and third concaves17, 67 is determined in such a manner that the edges of the first andthird dam members 16, 66 may not directly come into contact with eachother even if the first and third pressing rubbers 15, 65 deform whenthe object to be pressed 30 is pressed at the predetermined pressure.Therefore, the first pressing head 10 descends as long as the first andthird pressing rubbers 15, 65 continue to deform, and after the firstand third pressing rubbers 15, 65 have stopped deformation, the forcefor lowering the first pressing head 10 converts into the force forpressing the object to be pressed 30 (FIG. 8( c)).

Even if the edge of the protective film 5 extends over the openings 18,68 and the edges of the first and third dam members 16, 66 come intocontact with each other via the extending protective film 5, theprotective film 5 compressively deforms to ensure that the object to bepressed 30 is continuously pressed so far as the protective film 5 isformed from a compressively deformable material.

When the object to be pressed 30 is pressed, the surfaces of the firstand third pressing rubbers 15, 65 bulge, but the bulging parts of thefirst and third pressing rubbers 15, 65 are stopped by the first andthird dam members 16, 66 because the edges of the first and third dammembers 16, 66 project from the surfaces of the first and third pressingrubbers 15, 65. Thus, this compression bonding device 6 also preventshorizontal extension of the first and third pressing rubbers 15, 65 andmisalignment of the electric components 32, 33.

Heating means is provided on either one or both of the first and thirdpressing heads 10, 60 so that the electric components 32, 33 are notonly electrically but also mechanically connected to the substrate 31 bypressing the object to be pressed 30 under heat in the same manner aswith the compression bonding device 1 according to the first embodiment,thereby obtaining an electric device 30 a.

The foregoing description relates to cases in which the first and thirdconcaves 17, 67 are formed before the first and third pressing rubbers15, 65 deform, but the embodiment is not limited to such cases.

Reference numeral 7 in FIG. 9( a) represents a compression bondingdevice according to a fourth embodiment. This compression bonding device7 has the same structure as that of the compression bonding device 6according to the third embodiment described above and the layout of thefirst and third pressing heads 10, 60 is also similar to that of thecompression bonding device 6 according to the third embodiment describedabove except that first and third compression members 46, 76 are placedbetween the first and third pressing plates 12, 62 and the first andthird pressing rubbers 15, 65.

The structure and layout of the first and third compression members 46,76 are similar to those of the first compression member 46 of thecompression bonding device 4 according to the second embodiment. Whenthe object to be pressed 30 is sandwiched between the first and thirdpressing rubbers 15, 65, the first and third compression members 46, 76are compressed to reduce the thickness and the first and third pressingrubbers 15, 65 are pressed against the first and third pressing plates12, 62 and move with the movable plate 47, 77 in the holes 19, 69 beforethe first and third pressing rubbers 15, 65 deform.

FIG. 9( b) shows a state in which the first and third compressionmembers 46, 76 have reduced the thickness before the first and thirdpressing rubbers 15, 65 deform. The first and third pressing rubbers 15,65 get close to the first and second pressing plates 12, 62 to formconcaves which have the surfaces of the first and third pressing rubbers15, 65 as bottom faces and the first and third dam member 16, 66 as sidewalls.

The total of the depths of the concaves here (i.e., the total of theheight from the surface of the first pressing rubber 15 to the edge ofthe first dam member 16 plus the height from the surface of the thirdpressing rubber 65 to the edge of the third dam member 66 when the firstand third compression members 46, 76 are compressed) is smaller than thethickness of the object to be pressed 30, including the protective film5 on the surface of the third pressing rubber 65 and the protective film5 on the front face of the object to be pressed 30.

When the first and third compression members 46, 76 are compressed, theedges of the first and third dam members 16, 66 do not come into contactwith each other and nothing prevents the first pressing head 10 fromdescending. Therefore, when the first pressing head 10 is furtherlowered, the first and third pressing rubbers 15, 65 more closer to eachother and the first and third pressing rubbers 15, 65 in contact withthe electric components 32 are depressed. Finally, all of the electriccomponents 32, 33 are pressed by the first and third pressing rubbers15, 65.

The total of the depths of the concaves described above is determined insuch a manner that the edges of the first and third dam members 16, 66may not directly come into contact with each other and that apredetermined pressure may be applied to the object to be pressed 30.Therefore, if the object to be pressed 30 is continuously pressed underheat, the electric components 32, 33 are connected to the substrate 31to obtain an electric device 30 a in the same manner as with thecompression bonding device 1 according to the first embodiment.

When the electric components 32, 33 are pressed by the first and thirdpressing rubbers 15, 65, the parts of the first and third pressingrubbers 15, 65 out of contact with electric components 32, 33 bulge.However, the first and third pressing rubbers 15, 65 are stopped by thefirst and third dam members 16, 66 and do not extend horizontallybecause the first and third dam members 16, 66 project from the firstand third pressing rubbers 15, 65 when the electric components 32, 33are pressed. Thus, this compression bonding device 7 also preventsmisalignment of electric components 32, 33, thereby obtaining a highlyreliable electric device 30 a.

The foregoing description relates to cases in which at least the firstpressing rubber 15 is preliminarily surrounded by the first dam members16, but the embodiment is not limited to such cases.

Reference numeral 8 in FIG. 10( a) represents a compression bondingdevice according to a fifth embodiment, and this compression bondingdevice 8 has fourth and fifth pressing heads 80, 90 and a dam member 86.

The fourth and fifth pressing heads 80, 90 has fourth and fifth metalpressing plates 82, 92, and fourth and fifth pressing rubbers 85, 95placed on the fourth and fifth pressing plates 82, 92, wherein nothingis placed around the fourth and fifth pressing rubbers 85, 95 so thatthe side faces of the fourth and fifth pressing rubbers 85, 95 areexposed.

The planar shapes of the surfaces of the fourth and fifth pressingrubbers 85, 95 are identical or similar.

As shown in FIG. 11, the dam member 86 is tubular and the openings atboth ends of the tube has the same shape as those of the surfaces of thefourth and fifth pressing rubbers 85, 95 or a similar shape slightlylarger than them. Thus, at least surface parts of the fourth and fifthpressing rubbers 85, 95 can be inserted into the openings of the dammember 86.

Here, the side faces of the fourth and fifth pressing rubbers 85, 95 arenearly perpendicular to their surfaces, and the planar shapes of thefourth and fifth pressing rubbers 85, 95 cut in a direction parallel tothe surfaces are nearly uniform from the surface to the bottom face.

The dam member 86 has an inner wall face nearly perpendicular to theopenings at both ends and the sectional shape cut in a directionparallel to the openings is nearly uniform from one end to the other sothat not only surface parts but also the side faces of the fourth andfifth pressing rubbers 85, 95 can be inserted into the dam member 86.

The fourth pressing head 80 is placed while the side, on which thefourth pressing rubber 85 is placed, is faced downward. The platform 9lies below the fourth pressing head 80, and the fifth pressing head 90is placed on the platform 9 while the side, on which the fifth pressingrubber 95 is placed, is faced upward.

The fourth pressing rubber 85 is inserted into the tube from one end ofthe dam member 86 by transferring means (not shown), and the dam member86 is fitted to the fourth pressing head 80. In this state, the otherend of the dam member 86 projects below the surface of the fourthpressing rubber 85.

The protective film 5 is placed on the surface of the fifth pressingrubber 95, then the object to be pressed 30 is placed on the protectivefilm 5, and the protective film 5 is further placed on the front face ofthe object to be pressed 30. When the dam member 86 is lowered with thefourth pressing head 80 after an alignment has been made in such amanner that the outer periphery of the surface of the fifth pressingrubber 95 may lie in the opening at the lower end of the dam member 86,the object to be pressed 30 is inserted into the dam member 86, wherebythe fourth pressing rubber 85 comes into contact with the object to bepressed 30 via the protective film 5.

The length of the tube of the dam member 86 is such that the lower endmay be flush with or project below the surface of the fifth pressingrubber 95 when the fourth pressing rubber 85 comes into contact with theobject to be pressed 30 before the fourth and fifth pressing rubbers 85,95 deform, whereby the electric components 32, 33 are less likely to bemisaligned because the fourth and fifth pressing rubbers 85, 95 do nothorizontally extend when the object to be pressed 30 is pressed in thesame manner as with the compression bonding device 1 according to thefirst embodiment described above.

The foregoing description relates to cases in which the dam member 86 isintegrally molded in a tubular form, but the embodiments are not limitedto such cases.

Reference numeral 96 in FIG. 12 represents another embodiment of a dammember, and the dam member 96 has multiple plate-shape wall members 99,and the wall members 99 are arranged along the side face of the fourthpressing rubber 85 with their surfaces vertically directed and fitted tothe fourth pressing plate 82 by moving means not shown, to form a tubesurrounding the fourth pressing rubber 85.

In this state, the lower end of each wall member 99 projects below thesurface of the fourth pressing rubber 85 so that the lower end of thetube surrounding the fourth pressing rubber 85 projects below thesurface of the fourth pressing rubber 85 and the object to be pressed 30and the fifth pressing rubber 95 can be inserted into the downwardprojecting part.

The foregoing description relates to cases in which dam members 86, 96are provided on the fourth pressing head 80, but the embodiments are notlimited to such cases, and the dam members 86, 96 may be placed tosurround the fifth pressing rubber 95 and project above the surface ofthe fifth pressing rubber 95 at one end, in which case when the fourthpressing head 80 is lowered, the fourth pressing rubber 85 is enteredinto a concave formed by the dam members 86, 96 and the surface of thefifth pressing rubber 95.

Alternatively, the dam members 86, 96 may be fitted to neither fourthnor fifth pressing head 80, 90, but surround the fourth and fifthpressing rubbers 85, 95 after the fourth and fifth pressing rubbers 85,95 are opposed on both sides of the object to be pressed 30 beforepressing of the object to be pressed 30 starts.

Alternatively, the object to be pressed 30 may be pressed after the dammembers 86, 96 have been fitted to the fourth and fifth pressing rubbers85, 95, respectively. In this case, the dam members 86, 96 fitted to thefourth and fifth pressing rubbers 85, 95 preferably have the samestructure and layout as those of the first and third dam members 16, 66of the compression bonding device 6 according to the third embodimentdescribed above.

The length of the dam members 86, 96 and the layout of the dam members86, 96 are not specifically limited, either, and the fourth and fifthpressing rubbers 85, 95 may be entirely surrounded from the front faceto the bottom face or not only the fourth and fifth pressing rubbers 85,95 but also the fourth and fifth pressing plates 82, 92 may besurrounded so far as at least the surface parts of the fourth and fifthpressing rubbers 85, 95 are surrounded when the object to be pressed 30is pressed.

Also in the compression bonding device 8 according to the fifthembodiment, the fourth and fifth pressing rubbers 85, 95 may be directlyfitted to the fourth and fifth pressing plates 82, 92 or a compressionmember may be provided between the fourth and fifth pressing plates 82,92 and the fourth and fifth pressing rubbers 85, 95 as described for thecompression bonding device 7 according to the fourth embodiment.

The foregoing description relates to cases in which the first and thirdto fifth pressing rubbers 15, 65, 85, 95 are entirely surrounded by thedam members 16, 66, 86, 96, but the embodiments are not limited to suchcases, and one or more slits 98 may be formed in the dam members 16, 66,86, 96 so as to partially expose the side faces of the first and thirdto fifth pressing rubbers 15, 65, 85, 95 as shown in FIG. 13 so far ashorizontal extension of the first and third to fifth pressing rubbers15, 65, 85, 95 can be prevented.

The shape and size of the protective film 5 are not specificallylimited, and if any contact can be avoided between the adhesive film 35and the first to fifth pressing rubbers 15, 25, 65, 85, 95, a protectivefilm 5 having a size that does not extend over the surface of the firstto fifth pressing rubbers 15, 25, 65, 85, 95 may be used, or theprotective film 5 covering only the partial surface of the object to bepressed 30 may be used.

If the adhesiveness between the adhesive film 35 and the first to fifthpressing rubbers 15, 25, 65, 85, 95 used is low, any one or more of thefirst to fifth pressing rubbers 15, 25, 65, 85, 95 may be brought intodirect contact with the object to be pressed 30 without using theprotective film 5.

As a method of decreasing the adhesiveness between the first to fifthpressing rubbers 15, 25, 65, 85, 95 and the adhesive film 35, thematerials from which the first to fifth pressing rubbers 15, 25, 65, 85,95 are formed may be changed to those having low adhesiveness to theadhesive film 35 or a release layer having releasability against theadhesive film 35 may be provided on the surfaces of the first to fifthpressing rubbers 15, 25, 65, 85, 95.

The location where the heating means is provided is not specificallylimited, and it may be provided on either one or both of two pressingheads (first and second pressing heads 10, 20, first and third pressingheads 10, 60, or fourth and fifth pressing heads 80, 90) or provided onthe platform 9 if it can transfer heat. Alternatively, the adhesive film35 may be heated by external infrared radiation.

The adhesive film 35 may contain either one or both of a thermoplasticresin and a thermosetting resin.

The types of the thermosetting resin and thermoplastic resin are notspecifically limited, but one or more thermosetting resins such as epoxyresins, acrylic resins and urethane resins and one or more thermoplasticresins such as phenoxy resins, polyvinyl alcohols can be used.

Instead of using the adhesive film 35, a pasty adhesive may be appliedon the front face of the substrate 31 and then electric components maybe bonded to the adhesive to form an object to be pressed 30.

Moreover, an adhesive film 35 having electrically conductive particlesdispersed therein may be used and the electric components 32, 33 may beelectrically connected to the substrate 31 by sandwiching theelectrically conductive particles between connection terminals 37, 38 ofthe electric components 32, 33 and the connection terminal 37 of thesubstrate 31.

The type of the protective film is not specifically limited, butpreferably has releasability against the adhesive film 35 describedabove, e.g., a formed film of polytetrafluoroethylene or a formed filmof silicone rubber can be used.

The elastic materials forming the first to fifth pressing rubbers 15,25, 65, 85, 95 are not specifically limited, but elastomers havingrubber hardnesses (according to JIS S 6050) of 40, 80 could be used byway of example.

Rubber hardness is determined by the method described in “6. Testmethod” in JIS S 6050:2002, as follows.

Samples having stood for 24 hours or more after production are used forthe test. General matters common to chemical analyses are as shown inJIS K 0050. A hardness tester is used in a test for hardness. Thesurface of a test sample piece horizontally held is brought into contactwith the pressurizing face while the intender point of the tester isvertical. Then, the scale is immediately read as a positive number. Asto the measurement point of the test sample piece, the entire surface ofthe test sample piece is divided into three, each center portion ismeasured individually, and then their median values become hardness ofthe test sample piece.

The hardness tester here refers to a spring hardness tester having asemi-circular indenter point of 5.08 mm±0.02 mm in diameter. The heightof the indenter point is 2.54±0.22 mm at scale 0, and 0 mm at scale 100.The relationship between scale and spring force is shown in Table 1below.

TABLE 1 Tab. 1 Relationship between scale and spring force Scale 0 10 2025 30 40 50 60 70 75 80 90 100 Spring force N 0.54 1.32 2.11 2.50 2.893.68 4.46 5.25 6.03 6.42 6.82 7.60 8.39

When elastomers having rubber hardnesses of 40, 60, 80 were measured forrubber hardness every 30° C. in the range of the measurement temperatureof 30° C. to 240° C., the rubber hardness varied within +2. It can besaid that the rubber hardness is not influenced by temperature changes,because this value is within measurement error.

Elastomers used for the first to fifth pressing rubbers 15, 25, 65, 85,95 may include both natural and synthetic rubbers, and preferablysilicone rubber in terms of heat resistance and pressure resistance.

The first to fifth pressing rubbers 15, 25, 65, 85, 95 may be formedfrom the same material having the same rubber hardness or may be formedfrom different materials having different rubber hardnesses.

The type of the substrate 31 used in the embodiments is not specificallylimited, either, and various substrates such as rigid substrates andflexible substrate can be used.

The types of the electric components 32, 33 to be connected to thesubstrate 31 are not specifically limited, and specifically includesemiconductor elements, resistor elements, other substrates, etc.

Other electric components such as CR components may be connected toeither one or both of the front face or the rear face of the substrate31, before connecting the electric components 32, 33 to the front faceand the rear face of the substrate 31, while starting connecting theelectric components 32, 33 to the rear face of the substrate 31 afterconnecting the electric components 32, 33 to the front face of thesubstrate 31, or after connecting the electric components 32, 33 to bothof the front face and the rear face of the substrate 31.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present invention andwithout diminishing its intended advantages. It is therefore intendedthat such changes and modifications be covered by the appended claims.

1. A compression bonding device comprising: first and second pressingrubbers configured so that an object to be pressed which is placedbetween the first and second pressing rubbers can be pressed by thefirst and second pressing rubbers; and a dam member positioned higherthan a surface level of the first pressing rubber is placed around thefirst pressing rubber, wherein the second pressing rubber can beinserted into a space surrounded by the dam member.
 2. The compressionbonding device according to claim 1, wherein the first pressing rubberis placed on a first pressing plate, wherein a first compression member,which is compressively deformable, is placed between the first pressingrubber and the first pressing plate, and wherein the first dam memberbecomes higher than the surface level of the first pressing rubber atleast when the first compression member is compressed.
 3. A compressionbonding device comprising: first and third pressing rubbers configuredso that an object to be pressed which is placed between the first andthird pressing rubbers can be pressed by the first and third pressingrubbers; and a dam member positioned higher than a surface level of eachof the first and third pressing rubbers is placed around each of thefirst and third pressing rubbers.
 4. The compression bonding deviceaccording to claim 3, wherein the first pressing rubber is placed on afirst pressing plate, wherein a first compression member, which iscompressively deformable, is placed between the first pressing rubberand the first pressing plate, and wherein the first dam member becomeshigher than the surface level of the first pressing rubber at least whenthe first compression member is compressed.
 5. A compression bondingdevice comprising: fourth and fifth pressing rubbers configured so thatan object to be pressed which is placed between the fourth and fifthpressing rubbers can be pressed by the fourth and fifth pressingrubbers, a dam member surrounding the fourth and fifth pressing rubbers;and the dam member is separable from the fourth and fifth pressingrubbers.
 6. The compression bonding device according to claim 5, whereinthe dam member is tubular, and wherein the fourth and fifth pressingrubbers can be inserted into the tube of the dam member.